Are you asking why is there a requirement for a complete graph? or why is the check-tsp-map function called where it is? Brandon ... that s,

Message 1 of 5
, Dec 4, 2003

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Are you asking "why is there a requirement for a complete graph?"
or "why is the check-tsp-map function called where it is?"

Brandon

--- In aima-talk@yahoogroups.com, "chenyu468" <chenyu468@y...> wrote:
> Hello,
> I am studying "/search/domains/tsp.lisp" source code, which is
> about "Travelling salesperson Problem".
>
> In the source code, there is a requirement to the city map,
that's,
> the map should be complete graph. Every city is connected to every
> other city, in the function ( check-tsp-map?).
>
> I don't know why the requirement should be added here? What's the
> reason behind it. Could you help me?
>
>
> Thank you for your attention.
> kind regards/chenyu

chenyu468

hello, I am asking why is there a requirement for a complete graph? kind regards/chenyu ... every

> Are you asking "why is there a requirement for a complete graph?"
> or "why is the check-tsp-map function called where it is?"
>
> Brandon
>
> --- In aima-talk@yahoogroups.com, "chenyu468" <chenyu468@y...>

wrote:

> > Hello,
> > I am studying "/search/domains/tsp.lisp" source code, which is
> > about "Travelling salesperson Problem".
> >
> > In the source code, there is a requirement to the city map,
> that's,
> > the map should be complete graph. Every city is connected to

A TSP does not require a complete graph, but it becomes more difficult to solve it otherwise**. For instance, a fast but effective algorithm like 2-Opt (that

Message 3 of 5
, Dec 8, 2003

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A TSP does not require a complete graph, but it becomes more difficult
to solve it otherwise**. For instance, a fast but effective algorithm
like 2-Opt (that hill-climbs by inverting subsequences along the path)
would be rendered ineffective if the graph was not complete. You would
have to start checking constraints on the path at each exchange, which
requires different techniques (perhaps a constraint satisfaction
problem).

Best regards,
Brandon

** Source: Michalwicz, Zbigniew and Fogel, David B.; How to Solve It:
Modern Heuristics, Springer-Verlag, 1999.

--- In aima-talk@yahoogroups.com, "chenyu468" <chenyu468@y...> wrote:
> hello,
> I am asking "why is there a requirement for a complete graph?"